Snap action switch



Jan. 8, 1952 G. M. HAUSLER 2,582,034

SNAP ACTION SWITCH 7 Filed Jan. 8, 1949 ruwulnhuinwul Inventor:

Geor' e M. .Hausler,

by wJ/M His Attorney.

Patented Jan. 8, 1952 SNAP ACTION SWITCH George M. Hausler, Schenectady,N. Y., assignor to General Electric Company, a corporation of New YorkApplication January 8, 1949, Serial No. 39,922

Claims.

This invention relates to electrical switches and more particularly toan improved snap action switch providing positive contact pressure untilthe moment of operation.

Such switches are used for pressure, float, temperature, and otherapplications where the operating means travels slowly but the contactsmust snap quickly and positively.

It is an object of this invention to provide an improved snap actionswitch having the characteristics outlined above.

It is a further object to provide such a switch with a minimum ofoperating parts readily adapted to low cost manufacturing methods.

In general, my invention comprises a unitary, flat, resilient actuatedmember in a snap action switch which member provides the switch withpositive contact pressure until the moment of operation.

For a complete understanding of this invention, reference should be hadto the following specification and the accompanying drawing in whichlikeelements are given the same reference character throughout theseveral views.

In this drawing, Fig. 1 is a side elevation partly in section of aswitch illustrative of my invention; Fig. 2 is a sectional view taken online 2--2 of the Fig. 1; Fig. 3 is a plan view with cover removed ofFig. 1; Fig. 4 is a side elevation showing the contacts in openposition; Fig. 5 is a side elevation partly in section of a singlecontact switch in accordance with my invention; Fig. 6 is a sectionalview taken on line 6-6 of Fig. 5; and Fig. 7 is a plan view with coverremoved of Fig. 5.

Referring to the drawing, my improved switch I comprises a unitary,fiat, resilient actuated member 2 biased against and supported by aresilient, u-shaped support member 3 by means of a flat, L-shaped,resilient spring member 4 actuated by an actuating member 5. Actuatedmember 2 comprises an integral strip of thin material slottedlongitudinally to form two tension arms 43 and 44, two pivot compressionarms 28 and 29, and an actuated compression arm 23, all of the armsbeing substantially parallel, as shown in Fig. 3. Actuated member 2 isfurther provided with a projection 32 centrally located at one end ofactuated member 2, as shown in Fig. 3. Each of the tension arms 43 and44 has its ends connected to opposite ends of the actuated member 2.Each of the pivot arms 28 and 29 has one end inwardly disposed and itsother end connected to end 33 of the actuated member 2. The actuatedcompression arm 23 has one end inwardly disposed and its other endconnected to the opposite end of actuated member 2 from end 33. I havefound that to provide a proper snap action of actuated member 2, it ispreferable that the inwardly disposed ends of pivot compression arms 28and 29 extend some distance beyond the inwardly disposed end of actuatedcompression arm 23. This snap action will be described in detail later.One or more contacts 6 are secured to end 33 of actuated member 2, asshown in Fig. 3. Fig. 1 shows the contacts 6 in closed position. As theactuating member 5 is depressed, positive contact pressure is maintaineduntil the actuated member 2 snaps to the position shown in Fig. 4 andthe contacts 6 are thereby opened. When pressure on the actuating member5 is released, the reverse action takes place.

For a complete understanding of the structure of switch I, attention isnow directed to Figs. 1 and 3 wherein it may be seen that I provide arectangular mounting plate I on the outer surfaceof which are securedterminals 9 and Ill. Terminals 9 and ID are located adjacent to thesides at one end of mounting plate 1. Each of the terminals 9 and I9 isprovided with an aperture to accommodate terminal screws l2. In order toprovide space for the threaded end of terminal screws l2 when secured interminals 9 and I0, U-shaped notches l3 are provided at the sides ofmounting plate I, as shown in Fig. 4.

To secure support member 3 to mounting plate I a rivet l4 and screw I5pass through suitable aligned apertures in mounting plate I and supportmember 3. A recess 8 is provided in the face of support member 1adjacent to support member 3 and screw l5, as shown in Fig. 1. Thereason for this recess will be explained in detail later.

To secure terminals 9 and ID to mounting plate I, I bend portions l8 andI1 respectively of terminals 9 and I0 into opposed U-shapes, one leg ofeach U-shaped portion lying against the outside surface and one leg ofeach against the inside surface of mounting plate I. Screws It or othersuitable means are passed through aligned apertures in the legs ofU-shaped portions 16 and I1 and the mounting plate I. The heads ofscrews l8 are suitably plated to form contact buttons l9 electricallyconnected to terminals 9 and II].

In order to open and close a circuit connected to terminals 9 and I0,actuated member 2 s biased against the shorter leg 20 of support member3 by means of spring member 4. To accomplish this, spring member 4 hasits end 2! bent downward at approximately a right angle, as shown inFig. 1, and its end 22 bent in a concave manner with respect to actuatedcompression arm 23 of actuated member 2, also as shown in Fig. 1. Toprovide stability in actuated member 2 and spring member 4, a notch 24is provided in the longer leg 25 of support member 3, and a notch 26 isprovided in the inwardly disposed end o1 actuated compression arm 23 ofactuated member 2. Notches 24 and 26 respectively receive the ends 2|and 22 of spring member 4, as shown in Fig. 3. Also leg 20 of supportmember 3 is formed with pivot bends 21 to receive the inwardly disposedends of pivot compression arms 28 and 23 of actuated member 2. Springmember 4 is tapered in order that ends 2| and 22 will fit in respectiveslots 24 and 26.

The recess 8 adjacent to support member 3 is provided in order that thebends 21 of short leg 20 of support member 3 may be adjusted by means ofscrew I5 to a position nearer to or farther from the longer leg 25 ofthe same member. For example, by tightening screw l5, bends 21 ofsupport member 3 are moved in the direction of long leg 25, whileloosening screw I5 moves bends 21 in the opposite direction. Thus aproper bias between spring member 4 and actuated member 2 is attained.

Actuated member 2 is formed in one integral piece and, in order toprovide space for operation of the same, leg 20 of support member 3 isprovided with a recess 30, as shown in Fig. 3. Leg 25 of support member3 is provided with a rectangular aperture 3| to receive a projection 32of actuated vmember 2 and to limit the movement of projection 32 withinthe vertical dimension of aperture 3| when the actuated member 2 isoperated. Movement of end 33 of actuated member 2 is limited by contactbuttons l3 and a stop 34 which stop is made of suitable insulatingmaterial and secured to a recessed housing 35, also of any suitableinsulating material. Stop 34 is positioned in the path of end 33 ofactuated member 2 at a proper distance from contact buttons l3 toprovide satisfactory operation of actuated member 2.

Housing 35 is provided with a projecting portion 33 aligned above thecurved portion 31 of spring member 4. Portion 36 oi. housing 35 isprovided with a cylindrical aperture or sleeve 38 which acts as a guidefor actuating member 5. The lower portion 39 of actuating member 5 ismade larger in diameter than the portion which slides in the aperture 38in order that the inner surface of housing 35 may act as a stop limitingthe upward motion of actuating member 5.-

Housing 35 is secured to mounting plate I by nuts 40 and bolts 4|passing through aligned apertures in the mounting plate and housing orby any other suitable means.

To show the manner of operation of switch attention is directed to Figs.1, 2 and 4 in order. In Figs. 1 and 2, contacts 6 are closed uponcontact buttons l9 and the circuit between terminals 3 and I is closed.As actuating member is depressed, end 22 of spring member 4 is presseddownward carrying the end of leg 23 of the actuated member 2 downwardalso.

When the free end of actuated arm 23 of actuated member 2 is broughtinto a line with tension arms 43 and 44 of actuated member 2 theposition of end 32 of actuated member 2 becomes unstable and furthermovement of actuated arm 23 in a downward direction results in end 32 ofactuated member 2 snapping upward. However,

the contacts 6 maintain positive pressure on contact buttons l8 untilthe end 32 of actuated member 2 passes through a point of alignment withthe pivot point 21, which in the illustrated embodiment coincidessubstantially with the center of aperture 3|. At this time the movementof end 32 is uncontrolled and end 33 of actuated member 2 snaps upwardthereby opening contacts 6. Movement of end 32 of actuated member 2 islimited by the rectangular aperture 3| in leg 25 of support member 3 andmovement of end 33 of actuated member 2 is limited by stop 34. Theoperating mechanism of switch is then in the position shown in Fig. 4.

To close contacts 3, actuating member 5 is released and by bias ofactuated member 2 moves upward thus allowing the inwardly disposed endof actuated compression arm 23 of actuated member 2 to move upward. Whenthe end of arm 23 of actuated member 2 passes the central balance pointagain, the reverse action takes place and contacts 6 are returned to theclosed position shown in Fig. 1.

To show the manner in which the switch may be adapted to a single breakcircuit, Figs. 5, 6 and '7 are provided. In this form of my invention, asingle contact 6 is provided on the actuated member 2 and a terminal 42carrying a single contact button I9 is secured to mounting plate 1adjacent one end thereof. Centrally located in the opposite end ofmounting plate I a terminal 45 is provided. Terminal 45 is apertured toaccommodate a terminal screw I2, and mounting plate I has a U-shapednotch l3 to provide space for the threaded end of screw l2 when thelatter is in serted in the aperture in terminal 45. I

In order to secure terminal 45 to mounting plate I, a rivet l4 and screwl5 or other suitable means are provided, as shown in Fig. 5. Rivet l4and screw l5 pass through suitable aligned apertures in terminal 45,mounting plate I, and U-shaped support member 3 thus electricallyconnecting terminal 45 to support member 3 as well as securing both tothe mounting plate I.

In other respects, the single break switch shown in Figs. 5 to 7inclusive is the same as the double break switch shown in Figs. 1 to 4inclusive except that stop 34 in the case of the single break switch isformed as a projection centrally located on the end wall of housing 35and aligned in the path of end 33 of actuated member 2.

The switch may also be built as a single pole double throw switch bysubstituting another contact and terminal structure for stop 34.

From the above, it may be seen that I have provided a compact switchwhose mechanism comprises only 4 parts, namely an actuating member 5, aspring member 4, an actuated member 2, and a support member 3, allreadily manufactured at low cost and simple to assemble. Yet this switchprovides positive contact pressure until the moment of operation andtherefore is suitable for pressure, float, temperature and other applications where the operating means travels slowly but the contacts mustsnap quickly and positively to prevent arcing and destruction of thecontacts or damage to a motor connected to the switch.

As many changes could be made in the above construction withoutdeparting from the'scope of the invention, it is intended that allmatter contained in the above description be interpreted 'asillustrative and not in a limiting sense.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A snap action switch comprising a fixed contact and a movable contactcooperating therewith, a thin flat resilient member supporting saidmovable contact, said member having a plurality of longitudinal slotsdefining a plurality of compression arms, a plurality of tension armseach positioned between adjacent compression arms, said tension andcompression arms being substantially parallel, and a pair of transverseend portions each connected respectively to a different end of saidtension arms and connecting said tension arms to one end of each of saidcompression arms, a fixed support member engaging the other ends of aplurality of said compression arms, and a resilient movable memberengaging said fixed support member and engaging the other end of anotherof said compression arms, said fixed and movable members coacting inestablishing compression forces in said compression members, said endportions being movable between two positions responsive to movement ofsaid movable member, and said movable contact being supported on one ofsaid end portions.

2. A snap action switch comprising a fixed contact and a movable contactcooperating therewith, a thin flat resilient member supporting saidmovable contact, said member having a plurality of longitudinal slotsdefining a plurality of compression arms, a plurality of tension armseach positioned between adjacent compression arms, said tension andcompression arms being substantially parallel, and a pair of transverseend portions each connected respectively to a different end of saidtension arms and connecting said tension arms to one end of each of saidcompression arms, fixed members engaging the other ends of a pluralityof said compression arms, and a movable member engaging the other end ofanother of said compression arms, said fixed and movable membersestablishing compression forces in said compression members, said endportions being movable between two positions responsive to movement ofsaid movable member, and said movable contact being supported on one ofsaid end portions.

3. A snap action switch comprising a fixed contact and a movable contactcooperating there with, a thin fiat resilient member supporting saidmovable contact, said member having a pair of longitudinal slotsdefining a pair of compression arms, a tension arm, and a pair oftransverse end portions each connected respectively to a different endof said tension arm and connecting said tension arm to one end of eachof said compression arms, an adjustable resilient support memberengaging the other end of one of said compression arms, a movable memberengaged by said support member and engaging the other end of the otherof said compression arms, said other end of said other of saidcompression arms extending beyond the other end of said one compressionarm, said support and movable members cooperating in establishingcompression forces in said compression members, and means for adjustingsaid support member to vary the magnitude of said compression forces,said end portions being movable between two positions responsive tomovement of said movable member, and said movable contact beingsupported on one of said end ortions.

4. A snap action switch comprising a fixed contact and a movable contactcooperating therewith, a thin fiat resilient actuated member supportingsaid movable contact, said actuated member having a plurality oflongitudinal slots de- ,sion arms being substantially parallel, meanssupporting said actuated member comprising a U-shaped resilent supportmember positioned beneath said actuated member, one leg of said supportmember being located beneath and extending in the direction of saidopposite end of said actuated member, said one leg having an aper-- turetherein, the second leg of said support member being located beneath andextending in the direction of the inwardly disposed ends of said pivotcompression arms, a notch in said second leg to permit actuation of saidactuated member, bends in said second leg of said support memberarranged to engage the inwardly disposed ends of said pivot compressionarms, a flat L-shaped resilient spring member, the ends of said springmember being bent one over the free end of said actuated compression armand the other over the free end of said one leg of said support memberto move said actuated arm overcenter with respect to the other arms ofsaid actuated member thereby to cause the outer ends of said actuatedmember to move in a reverse direction with a snap action, means limitingthe movement of both ends of said actuated member in both directionsnormal to the plane of said actuated member and between two fixedpositions, said means comprising an outwardly disposed projection onsaid opposite end of said actuated member, said projection protrudingthrough said aperture in said one leg of said support member, and stopmeans located adjacent both surfaces of said one end of said actuatedmember and in the path of movement of said one end, an actuating memberengaging said spring member and arranged to move one end thereof towardthe plane of said actuated member thereby depressing the inwardlydisposed end of said actuated arm, and stop means limiting the reversemovement of said actuating member, whereby positive contact pressure ismaintained until the moment of operation of said movable contact.

5. A snap action switch comprising a fixed contact and a movable contactcooperating therewith, a thin fiat unitary resilient member supportingsaid movable contact, said member hav-- ing at least one tension arm,and at least one actuated compression arm and a plurality of pivotcompression arms formed integrally with said tension arm andsubstantially parallel thereto, each of said pivot compression armshaving one end inwardly disposed and its other end joined to one end ofsaid tension arm, said actuated compression arm having one end inwardlydisposed and its other end joined to the other end of said tension arm,a fixed support member engaging the inwardly disposed ends of said pivotcompression arms, and a resilient movable member engaging the inwardlydisposed end of said actuated compression arm, said fixed support memberand said resilient movable member cooperating in establishingcompression forces in said compression arms and tension forces in saidtension arm, said end ortions of said tension arm being movable betweentwo positions responsive to movement or said movable member, mb and saidmovable contact being supported on one Re. 17 646 of said end portionsof said tension arm. 2

GEORGE M. HAUSLER. 3:233:32: 2.508.040

REFERENCES CITED UNITED STATES PATENTS I Name Date Johnsson Apr. 22,1930 Eaton Aug. 22, 1939 Johnson Jan. 14, 1941 Kaminky July 12, 1949Ransome May 16, 1950 FOREIGN PATENTS Country Date Switzerland Nov. 16,1939

